Large area die cutting press



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SGLENOID FIGA l '[;`,\"I`ORS EDGAR HAAS EUNARD KOTTSlEPER MQW/ ATTORNEYS United States Patent 3,472,109 LARGE AREA DIE CUTTING PRESS Edgar Haas, New York, N.Y., and Edward Kottsieper, Dresden Mills, Maine, assignors to Herman Schwabe,

Inc., Brooklyn, N.Y., a corporation of New York Filed Feb. 15, 1967, Ser. No. 616,257 Int. Cl. B26d 5/12; B30h 1/32 U.S. Cl. 83-540 13 Claims ABSTRACT 0F THE DISCLOSURE The die cutting press has a large area platen for die cutting large pieces of material such as automobile upholstery or clothing. The platen is moved by a considerable number of hydraulic power units each having a single acting piston and cylinder, and all Supplied simultaneously by a common motor driven pump. The return movement of the platen is provided by a plurality of adjustable springs. The mounting of the power units affordsl lateral self-adjustment as between the platen and cylinder of each unit, and the piston structure accommodates a slight tilt of the piston axis relative to the cylinder axis.

Heretofore a single large hydraulic power unit was used, and this required a platen of extremely heavy construction in order to maintain rigidity over a large area. Multiple power units were attempted but were not Successful because of a tendency to tilt, bind or lock.

In this die cutting press an array of power units is successfully employed by using single acting power units which `are self-adjustable both laterally and tiltably. The return movement is provided by multiple springs which are individually adjustable to help level or equalize the movement of the platen.

The foregoing and additional features are described in the following detailed specification, which is accompanied by drawings in which:

FIG. l is a front elevation of a large area die cutting press embodying features of the invention;

FIG. 2 is an end view of the same;

FIG. 3 is a partially sectioned elevation through one of hydraulic power units;

FIG. 4 represents the lower left portion of FIG. 3 drawn to larger scale to show the clearances;

FIG. 5 is a section through one of the return springs, and is taken approximately in the plane of the line 5-5 of FIG. 2; and

FIG. 6 is a diagram showing how all of the power units are simultaneously supplied -with fluid from a single pump.

Referring to the drawing, and more particularly to FIGS. 1 and 2, the die cutting press has a large area table 12, and a large area beam 14 spaced thereover by appropriate frame members 16. The table 12 is rigid, it being supported by or forming a part of the beam-like structure 18.

A large area platen 20 is disposed between table 12 and beam 14, and is driven by a plurality of single-acting hydraulic piston and cylinder power units 22 disposed between the bottom surface of the beam 14 and the platen 20. These cause the downward or cutting movement, whereas the upward or return movement is caused by a plurality of springs 24. A motor 26 drives a pump which preferably is submerged in a tank or reservoir of hydraulic uid, the uid being supplied through a solenoid-operated valve 28 to all of the power units 22.

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Considering the arrangement in greater detail, the frame in this case is of the four-poster type, there being a rigid base 30 carrying four upright corner rods 16 on which the beam 14 is ixedly mounted by nuts 32. The height of the table 12 may be adjusted, as by means of parallel shafts 34 which are geared together and are driven in unison by a crank (not shown), and which turn four worms meshing with four -worm gears 36 which act as nuts to raise or lower the table. The posts are threaded to receive the said gear driven nuts. This construction for adjustment of table height is known, and therefore requires n-o further detailed description.

Referring now to FIG. 3, the hydraulic unit is preferably inverted, the hollow piston 40 being on top and the cylinder 42 on bottom. The piston and cylinder each has a flange 44 and 46, the flange 44 being secured to the beam 14, and the flange 46 being secured to the platen 20. Flange 44 is fxedly bolted in position, as by means of a ring of screws or bolts 48. The flange 46 is held by a retainer ring 50 which is ixedly bolted in position, as by means of screws or bolts 52.

As will be seen in FIG. 4, there is a vertical clearance at 54 between the flange 46 and the ring 50 even when the ring S0 is bolted down tightly against the platen 20. In a typical case, this clearance may be about three thousandths of an inch, and it affords some lateral or horizontal self-adjustment, there being ample clearance at 56 for this purpose, say one-sixteenth or even oneeighth inch.

In FIG. 3 it will be seen that the eEective height of that part of the piston wall which -cooperates with the cylinder is very short in axial dimension, relative to its diameter. In the illustrated case the height is only about one-quarter of the diameter. The piston has only one piston ring, shown at 58. The piston is additionally sealed against leakage by the provision of two grooves carrying O-rings 60. Reverting to FIG. 4, there is considerable clearance between the piston 40 and the cylinder 42, as shown at 62, and in this particular case the clearance is approximately six thousandths of an inch.

This combination of features, that is the short height of the piston wall, the large radial clearance, and the single piston ring, make possible some slight self-adjustable tilt of the piston axis relative to the cylinder axis without binding or locking the piston and cylinder against movement.

In the particular case illustrated, the platen 20 is sixty inches long and forty inches wide, and it is moved by six power units symmetrically distributed over the platen, as is clearly shown in FIGS. 1 and 2. The power units may vary in diameter, depending on the total cutting force required for the press. The power units may be ve, six, or seven inches in diameter, and the hydraulic pressure supplied may be say two thousand pounds per square inch, or higher, up to say six thousand pounds per square inch. The total force on the platen therefore may be hundreds of tons, but it is distributed over the platen area, instead of being concentrated at the center of the platen.

The motor, reservoir, pump, solenoid valve7 and distribution pipes all are carried by the beam 14. They are located above the large area bottom of the beam.

The return movement of the platen is provided by springs, in this case six springs, with three located at each end as shown in FIGS. l and 2. One of the springs is illustrated in FIG. 5, the spring 24 being held by a rod 64 the lower end of which is l'ixedly secured to the platen 20, and the upper end of which passes slidably through the beam 14. The spring is a compression spring, the force of which may be adjusted by means of lock nuts 66. By appropriate adjustment of the nuts 66, the return force may be equalized to help level the platen 20, and to help equalize the travel of the ends of the platen.

The hydraulic system is simple and may be described with reference to FIG. 6. Motor 26 drives a preferably submerged pump 70 which delivers hydraulic fluid under pressure to a solenoid operated valve 28 which controls the ow to a distributor fitting 72. If desired multiple motors and pumps may be used in parallel for delivery at the same pressure but in greater volume for faster movement of the platen. Fitting 72 divides the ow into three pipes 74, 76 and 78, each of which extends to a T fitting and so to two pipes corresponding to two of the six power units. Each pipe, for example the pipe 80 in FIG. 6, may be connected by means of a pipe thread to a hole in the beam 14. Only the horizontal bottom portion of the beam 14 is represented in FIG. 6, the integral vertical sides which stiffen the beam being omitted in FIG. 6.

FIG. 3 shows that pipe 80 may be connected as indicated at 82 to a hole 84 in beam 14. This hole registers with a hole 86 in the top of piston 40, thus connecting pipe 80 to a power unit. Leakage is prevented by means of an O-ring 88 around each of the six holes. The center projection 90 is merely a pilot to accurately x the location of the power unit.

Reverting to FIG. 6, there is the usual relief valve 92. The reservoir or tank is represented at 94, it being understood that there is really only one such reservoir, and further that pump 70 may be immersed in the hydraulic fluid. When the solenoid is energized it moves a. valve spool to proper position to supply pressure fluid through fitting 72 to the six power units. When the solenoid is deenergized the spool is shifted, as by means of a return spring, to a position which permits the power units to empty through the valve to the tank, the actual motion of the power units then being caused by the six compression springs 24. At the same time the pump is discharging into the tank. When the platen is raised and is idle, the hydraulic fluid is circulated between the pump and the reservoir in accordance with the known and usual practice.

The motor 26 may be moderate in size, say five horsepower, but it is equipped with a flywheel which helps take care of the peak power requirement.

It is believed that the construction and operation of our improved large area die cutting press, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while we have shown and described the invention in a preferred form, changes may be made without departing from the scope of the invention.

We claim:

1. A large area die cutting press having a large area table, a large area beam spaced thereover by appropriate frame members, a large area platen therebetween, and means to drive the platen toward or away from the table, said means comprising a plurality of single acting hydraulic piston and cylinder power units between the beam and the platen for causing downward cutting movement, means providing clearances at each power unit such that the power units are self-adjustable relative to one another in directions transverse to their generally vertical power movement, a plurality of resilient means for causing upward movement of the platen, and a motor driven pump connected to distribution pipesfor supplying hydraulic fluid simultaneously to all of the power units.

2. A large area die cutting press as defined in claim 1, in which the piston and cylinder each has a flange, one fiange being secured to the beam and the other flange being seucred to the platen, one flange being fixedly bolted in position, and the other flange being held by a retainer ring which is fixedly bolted in position, and in which there is a clearance between the latter flange and the retainer ring affording self-adjustable lateral or horizontal movement relative to the platen and beam.

3. A large area die cutting press as defined in claim 2, in which the working portion of the piston wall has a very short axial dimension relative to its diameter, and has unusually large clearance between it and the cylinder, and Vin which the piston has only one piston ring and has one or more additional grooves with O-rings, whereby a slight tilt of the piston axis relative to the cylinder axis may be tolerated without locking the piston and cylinder against movement.

4. A large area die cutting press as defined in claim 3, in which the clearance between the flange and the retainer ring in vertical direction is of the order of three thousandths of an inch, and in horizontal direction is of the order of a sixteeth of an inch.

5. A large area die cutting press as defined in claim 4, in which the radial clearance between the piston and cylinder is approximately six thousandths of an inch, and in which the length of the cylinder is only about a fourth of its diameter.

6. A large area die cutting press as defined in claim S, in which the piston is fixedly bolted to the beam, and in which the cylinder is located beneath the piston and is adjustably secured to the platen by means of the retainer ring.

7. A large area die cutting press as defined in claim 6, in which each power unit has a hole at the top, and the beam has holes which register with those in the power unit, and in which the motor driven pump and an oil reservoir and a solenoid operated valve and distribution piping al1 are located above the beam, said distribution piping being connected to the holes in the beam, and in which each power unit is provided with an O-ring around the hole and clamped between the power unit and the beam to seal the same against escape of fluid.

8. A large area die cutting press as defined in claim 7, in which there are six power units symmetrically distributed on the platen, and in which there are six return springs symmetrically distributed on the platen and each having means to adjust its return force, whereby the forces may be equalized to help provide uniform travel of the parts of the platen.

9. A large area die cutting press as defined in claim 1, in which the working portion of the piston wall has a very short axial dimension relative to its diameter, and has unusually large clearance between it and the cylinder, and in which the piston has only one piston ring and has one or more additional grooves with O-rings, whereby a slight tilt of the piston axis relative to the cylinder axis may be tolerated without locking the piston and cylinder.

10. A large area die cutting press as defined in claim 2, in which the clearance between the flange and the retainer ring in vertical direction is of the order of three thousandths of an inch, and in horizontal direction is of the order of a sixteenth of an inch.

11. A large area die cutting press as defined in claim 9, in which the radial clearance between the piston and cylinder is approximately six thousanths of an inch, and in which the length of the cylinder is only about a fourth of its diameter.

12. A large area die cutting press as defined in claim 2, in which the piston is fixedly bolted to the beam, and in which the cylinder is located beneath the piston and is ahdjustably secured to the platen by means of the retainer ring.

13. A large area die cutting press as defined in claim 1, in which each power unit has a hole at the top, and the beam has holes which register with those in the power unit, and in which the motor driven pump and an oil reservoir and a solenoid operated valve and distribution piping all are located above the beam, said distribution piping being connected to the holes in the beam, and in which each power unit is provided with an O-ring around the hole and clamped between the power unit and the beam to seal the same against escape of fluid.

(References on following page) 5 6 References Cited 3,091,147 S/ 1963 Holl et al. 83-639 X UNITED STATES PATENTS 3,194,096 7/1965 Comet 83-588 X 10/ 1923 Prius 83-639 X FRANK T. YOST, PrmaryExaminer 10/ 1942 Maude 10U-269 X 5 5/1946 Iversen 83-639 X USC1XR 5/1951 Graham et al. 83--639 X 83-588, 590, 639; 10G- 266, 269 

